A house in Paris happens to have two families living there with the same last name. In one apartment lives opera singer Gambetta Duval with his two daughters, Jeanne and Nita. In the second apartment lives old lady Duval with her grandchild Philippa and an her lodger, the physician Leon Monnier. Jeanne is secretly in love with Dr. Monnier who is secretly in love with Nita, who is secretly having an affair with the great playwright Armand de Marny.
Homeowner Edlund is forced to borrow money from Mauritz Berg, the local sawmill owner, but soon finds it is not an end to his problems or his dealings with Berg.
This is the story of Olof Svensson who works as a streetcar conductor in Stockholm. In his free time he is a music composer.
